1. Field of Invention
The present invention relates to a method for receiving feedback and allocating radio resource corresponding to a multicast broadcast service. More particularly, the present invention relates to a method for receiving negative-acknowledgment-based feedback in form of a code division multiple access code.
2. Description of Related Art
The multicasting technique (one-source-many-destination) is widely utilized for multimedia content delivery in the Internet. In the recent years, a number of portal sites offer Internet protocol multicast services to be extended using wireless transmission to the mobile stations. With the aforementioned service, a wireless system broadcasts data packets to the subscriber stations and each subscriber station receives and processes the same stream of packets.
Normally, multicast and broadcast services (MBS) are offered in the downlink only. Subscriber stations either in awake/sleep mode or in idle mode should be able to receive the subscribed multicast and broadcast service flows. It has been shown in the literature that the number of synchronized transmitting cells in an MBS zone, the cell size, and the users' location distribution are factors that may affect the selection of modulation and coding scheme (MCS) state. Unfortunately, the network cannot dynamically allocate the radio resource (e.g., transmission power control, MCS state selection, HARQ parameter setting) due to the lack of a feedback mechanism. In order to enhance the spectral efficiency of MBS, a feedback mechanism with low signaling overhead is required for both awake/sleep and idle subscriber stations that receiving the same MBS service to report their service qualities.